Overview
In System Restore, the user may create a new restore point manually, roll back to an existing restore point, or change the System Restore configuration. Moreover, the restore itself can be undone. Old restore points are discarded in order to keep the volume's usage within the specified amount. For many users, this can provide restore points covering the past several weeks. Users concerned with performance or space usage may also opt to disable System Restore entirely. Files stored on volumes not monitored by System Restore are never backed up or restored.
System Restore backs up system files of certain extensions (.exe, .dll, etc.) and saves them for later recovery and use. It also backs up the registry and most drivers.
Read more about this topic: System Restore